Interpretive Summary: Interpretive Summary:
Efficient use of irrigation water is critical in the Western U.S. due to shortage of water supplies. Good irrigation scheduling is important for efficient water use. Scientific irrigation scheduling is often not used because it requires too much effort to accurately predict crop water use. An improved method is described in which satellite imagery is used in combination with evapotranspiration information from weather station networks to estimate crop water use and provide the information to growers and managers on a WEB site in a geographical format. This system is currently operational for 6 million hectares of California irrigation land. Users can click on a location on a map to learn the crop growth and estimated daily crop water use, and can view a graph of water use over the recent past as well as past years for that location. This WEB-based application provides growers with most of the information needed to accurately schedule their irrigation applications.

Technical Abstract:
Abstract:
The Satellite Irrigation Management Support (SIMS) project combines NASA's Terrestrial Observation and Prediction System (TOPS), Landsat and MODIS satellite imagery, and reference evapotranspiration from surface weather station networks to map daily crop irrigation demand in California in near real time. TOPS-SIMS currently maps crop fractional cover, basal crop coefficients, and basal crop evapotranspiration. Map products are generated at 30 meter resolution on a daily basis over approximately 15 million acres of California farmland. TOPS-SIMS is a fully operational prototype, and a publicly available beta-version of the web interface is being pilot tested by farmers, irrigation consultants, and water managers in California. Data products are distributed via dynamic web services, which support both visual mapping and time-series queries, to allow users to obtain information on spatial and temporal patterns in crop canopy development and water requirements. This system can be extended to other areas that have adequate ET weather networks.